Immunological Defects in Healthy Twin Siblings to Patients with Hodgkin's Disease

Abstract
The immunocompetence was studied of 6 healthy twins, whose monozygotic or dizygotic same-sexed twin partner had died from Hodgkin''s disease. Lymphocyte DNA synthesis induced by concanavalin A was markedly reduced at 3 different concentrations in all twins compared to an age-matched group of healthy controls. The lymphocyte response to pokeweed mitogen and to phytohemagglutinin was also impaired. PPD [purified protein derivative] induced lymphocyte DNA synthesis was low in 3 twins and correlated well with their delayed skin hypersensitivity to the antigen. One twin was completely anergic to 3 different skin antigens. The mean total blood lymphocyte count did not differ from that of controls. There was no change in T [thymus-derived]- or B [bone marrow-derived]-lymphocyte subpopulations. The presence of a functional lymphocyte deficiency in all twins strongly suggests that the immunodeficiency in Hodgkin''s disease is partly caused by genetic and/or environmental factors.